diff --git a/tests/bridge.test.mjs b/tests/bridge.test.mjs
index 479d717..5bb5261 100644
--- a/tests/bridge.test.mjs
+++ b/tests/bridge.test.mjs
@@ -93,8 +93,11 @@ test("pinned bridge assertion validates every exact claim and separates purposes
       ),
     );
   }
+  // A future `iat` must be rejected, but `now` is recomputed inside
+  // verifyAssertion. A one-second offset can be swallowed when the wall clock
+  // advances between capture and verification, so use a margin that cannot.
   for (const change of [
-    { iat: now + 1 },
+    { iat: now + 30 },
     { exp: now },
     { exp: now + 61 },
     { jti: "short" },